Aronia (chokeberry) is a deciduous shrub which belongs to the plant family Rosaceae. Within the genus Aronia several species and hybrids are known, such as Aronia melanocarpa (black chokeberry), Aronia arbutifolia (red chokeberry), and Aronia x prunifolia (purple chokeberry). The Aronia fruits are small pomes and the juice of it is known to be astringent and to have a high content of vitamin C and other antioxidants.
Due to their intensive fruit color Aronia is used as a coloring agent for beverages and other food products, as disclosed e.g. in U.S. Pat. No. 6,703,056, WO 2005 058052, and WO 2006 138419. Beside this, the Aronia fruits have awaken interest due to their antioxidative qualities. For example Aronia melanocarpa is known to have high contents of phenolic compounds, especially anthocyanins, which are mainly located in the skin of the berries for UV protection of the pulp and the seeds. These anthocyanins give Aronia melanocarpa an extraordinary antioxidative strength. A parameter showing the capacity of a compound or an extract to deal with oxidative stress is the oxygen radical absorbance capacity or ORAC. Aronia shows high ORAC values and is therefore also used/added as a functional food or nutraceutical. For example, US 2007 0020358 discloses a sports drink concentrate which may include Aronia as a nutraceutical ingredient. A functional sweetener composition comprising an Aronia extract as antioxidant is disclosed in WO 2007 06 1900, and WO 2007 076857 teaches a chewing gum composition containing Aronia which is used as a source of antioxidants.
Further thereto, it is known from the prior art that Aronia or compounds thereof may be used for the preparation of pharmaceutical compositions or nutraceutical compositions and food supplements. For example DE 10 2004 029 887 A1 discloses a dietary supplement on the basis of pomace comprising an extract of the skin of Aronia fruits which dietary supplement is described to have a high radical protection factor. DE 10 2004 052 882 A1 teaches a dietary supplement on the basis of a specific selection of fruit and legume concentrates, which comprises inter alia an Aronia fruit juice concentrate. Said dietary supplement is described to strengthen the immune system, wherein it is set forth that the combination of ingredients synergistically influences the impact of the ingredients.
WO 2001 015553 teaches that food supplements containing Aronia fruit extract may be used to inhibit an inflammation mediated by cyclooxygenase, i.e. it is disclosed that Aronia extracts have an anti-inflammatory activity due to an inhibition of COX-2 activity preferentially over COK-1 activity.
DE 10 2005 046 474 A1 teaches to use an extract of the fruit's skin of Aronia sp. for the prophylactic and therapeutic treatment of bacterial, mycotic and/or inflammatory diseases/conditions. The effect achieved is attributed to an antibacterial and antimycotic effect of said extract. A direct influence of the extract on the immune system is not disclosed.
In addition thereto, WO 2002 005827 teaches the use of Aronia extract for the preparation of a medicament for the treatment of brain cancer and further discloses a nutraceutical composition for the treatment of cancer comprising one or more flavonoids from Aronia and the micronutrients selenium and zinc.
Micronutrients are needed and involved, e.g. as cofactors for enzymes, in a plurality of metabolism processes and are therefore important ingredients in food. Accordingly, and as taught by the prior art, micronutrients may be added to different kinds of food for example to functional food in order to achieve or improve certain physiological functions.
As regards the immune system, it is known that the micronutrients selenium and zinc affect beside other physiological functions the immune status. Selenium is known to be required for a proper activity of neutrophils, macrophages, NK cells, T lymphocytes and some other immune mechanisms and an insufficient supply of selenium to the human body may result in a weakened immune system. Zinc is known to be an important ion for enzymes, proteins and transcription factors, and is therefore involved in many functions of the body also including immune responses.
As already indicated above, combinations of an Aronia extract with at least one micronutrient, in particular with selenium and/or zinc, are known from the prior art. However, this often seems to be a “combination by chance”. For example WO 2005 058052 and WO 2006 138419 teach the use of Aronia as a coloring agent, while zinc and selenium are comprised in a stabilizing mixture for the food product taught in these references. In other cases, the combination of Aronia extract with selenium and/or zinc as taught in the prior art may be considered just as a consequence of the purpose of the product. For example, the sports drink as disclosed in US 2007 0020358 teaches to use Aronia due to its high ORAC value, while selenium and zinc are added as micronutrients. Hence, these components are not taught in the prior art to be combined in order to achieve a certain effect, which results from the interrelated action of these components. In particular, the prior art does not seem to indicate that due to the selective combination of an Aronia extract with selenium and/or zinc, a composition having an improved immune stimulating effect may be obtained.
Even if different kinds of immune stimulating agents are known, there is an ongoing need for improved immune stimulating agents, since especially due to the increasing environmental stress of modern life the immune system of human beings is continuously exposed to various kinds of stress. Often agents based on a natural or biological basis are preferred to synthetic pharmaceutical products, because they are on the one hand often better accepted from the patient or the consumer and may be also manufactured in a more cost effective way, especially in the case when a plant extract may be used per se, since no chemical synthesis and/or purification of effective compounds is necessary.
Therefore, it is clear from the above that there is a need for improved substances or compositions having immune stimulating effects.